Flexible assembly for sprinklers

ABSTRACT

An assembly for connecting a sprinkler to a branch line of a fire suppression system includes a flexible conduit having one end attached to the branch line. The opposite end is attached to the sprinkler. The conduit is corrugated and has an outer surface with a plurality of crests and troughs. A sleeve co-axially surrounds a portion of the flexible conduit proximate to the sprinkler. The sleeve has a corrugated inwardly facing surface comprising a plurality of crests and troughs spaced so as to fit within the crests and troughs of the conduit and thereby prevent axial sliding motion of the sleeve relatively to the conduit. The sleeve and the flexible conduit are rotatable relatively to one another thereby preventing torque being applied to the flexible conduit through the sleeve.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 13/709,313, filed Dec. 10, 2012, now abandoned,which is based upon and claims priority to U.S. patent application Ser.No. 12/877,357, filed Sep. 8, 2010, now U.S. Pat. No. 8,336,920, whichis based upon and claims priority to U.S. Provisional Application No.61/241,615 filed Sep. 11, 2009 all of which are hereby incorporated byreference herein.

FIELD OF THE INVENTION

This invention relates to a flexible assembly for connecting sprinklersto branch lines in a fire suppression system.

BACKGROUND

Fire suppression sprinkler systems used, for example, in structures suchas office buildings, hotels, warehouses and private residences have apiping network comprising a riser pipe connected to a source ofpressurized fire suppressing fluid, for example, a liquid, such aswater, or a gas, such as halon. Branch pipe lines are connected to theriser pipe at each floor of the structure and extend throughout eachfloor so that fire suppressing fluid may be delivered through the branchlines to any location on each floor. The branch lines are usuallysuspended on hangers attached to the structural ceiling of each floor.Sprinklers, which serve to discharge the fluid in the event of a fire,are connected to the branch lines by flexible conduits. The use offlexible conduits provides a great advantage as it allows the positionof the sprinklers to be easily adjusted, both laterally and vertically,in relation to the decorative ceiling which may be suspended beneath thestructural ceiling of each floor. The flexible conduit saves time duringinstallation, as it obviates the need for the technician to install arigid pipe assembly, comprised of couplings and pipe segments, toconnect the branch line to each sprinkler head on the floor. With arigid pipe assembly even a minor miscalculation, either in the design orinstallation, can be aesthetically and functionally unacceptable, andrequire a redesign and reinstallation.

Although advantageous, flexible conduits used to connect sprinklers tobranch lines of fire suppression systems have certain drawbacks. Forexample, one disadvantage which occurs when flexible conduits are usedis the problem of over-torquing the conduit. The sprinklers may havethreaded connections and torque is applied to connect them to the end ofthe flexible conduit. Torque inadvertently applied to the conduit duringinstallation of the sprinkler may cause leaks to occur, for example, atthe fitting where the conduit is connected to the branch line.Additionally, torque may be applied to the flexible conduit as a resultof a seismic event such as an earthquake due to relative motion betweenthe branch line and the sprinkler. If the applied torque damages theflexible conduit, causing it to leak, that may prevent fire suppressingfluid from reaching other parts of the system where a fire has brokenout as a result of the event. It is advantageous to avoid applyingtorque to the flexible conduit to avoid damage. There is clearly a needfor a flexible assembly which avoids the disadvantages associated withknown flexible conduit.

SUMMARY

The invention concerns an assembly for connecting a sprinkler to abranch line of a fire suppression system. In one example embodiment, theassembly comprises a flexible conduit having a first end connectable tothe branch line, and a second end connectable to the sprinkler. Theflexible conduit has a corrugated outer surface. The corrugated outersurface comprises a plurality of first crests and troughs extendingcircumferentially around and defining a central space. The flexibleconduit provides fluid communication between the branch line and thesprinkler. An adapter is positioned between the sprinkler and the secondend of the flexible conduit for effecting attachment of the sprinkler tothe flexible conduit. A sleeve co-axially surrounds a portion of theflexible conduit proximate to the adapter. The sleeve has a corrugatedinwardly facing surface comprising a plurality of second crests andtroughs extending circumferentially and spaced so as to fit within thefirst crests and troughs and thereby prevent axial sliding motion of thesleeve relatively to the conduit. The sleeve and the flexible conduitare rotatable relatively to one another thereby preventing torque beingapplied to the flexible conduit through the sleeve.

In a particular example embodiment, the sleeve comprises a plurality offlat outwardly facing surfaces. In a specific example, the sleevecomprises six flat outwardly facing surfaces forming a hexagonal crosssection. The sleeve may also comprise a unitary body having a firstlongitudinally extending edge and a second longitudinally extending edgein facing relation with the first longitudinally extending edge. Thefirst longitudinally extending edge is positioned in spaced relation tothe second longitudinally extending edge so as to define a gaptherebetween.

In another example embodiment of an assembly for connecting a sprinklerto a branch line of a fire suppression system, the assembly comprises aflexible conduit having a first end connectable to the branch line, anda second end connectable to the sprinkler. The flexible conduit has acorrugated outer surface. The corrugated outer surface comprises aplurality of first crests and troughs extending helically around anddefining a central space. The flexible conduit provides fluidcommunication between the branch line and the sprinkler. An adapter ispositioned between the sprinkler and the second end of the flexibleconduit for effecting attachment of the sprinkler to the flexibleconduit. A sleeve co-axially surrounds a portion of the flexible conduitproximate to the adapter. The sleeve has a corrugated inwardly facingsurface comprising a plurality of second crests and troughs extendinghelically and spaced so as to fit within the first crests and troughsand thereby prevent axial sliding motion of the sleeve relatively to theconduit. The sleeve and the flexible conduit are rotatable relatively toone another thereby preventing torque being applied to the flexibleconduit through the sleeve.

In a particular example embodiment, the sleeve comprises a plurality offlat outwardly facing surfaces. In a specific example, the sleevecomprises six flat outwardly facing surfaces forming a hexagonal crosssection. The sleeve may also comprise a unitary body having a firstlongitudinally extending edge and a second longitudinally extending edgein facing relation with the first longitudinally extending edge. Thefirst longitudinally extending edge is positioned in spaced relation tothe second longitudinally extending edge so as to define a gaptherebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric/partial sectional view of an example embodimentof an assembly for connecting a sprinkler to a branch line of a firesuppression system according to the invention;

FIG. 1A is a partial view of an alternate embodiment of the assemblyshown in FIG. 1;

FIG. 2 is an exploded view of an example embodiment of an assemblyaccording to the invention;

FIG. 3 is an exploded isometric view of a portion of the embodiment ofthe assembly shown in FIG. 2;

FIG. 4 is a partial sectional view taken at line 4-4 of FIG. 3;

FIG. 5 is an exploded isometric view of a portion of an exampleembodiment of an assembly according to the invention;

FIG. 6 is an exploded isometric view of a portion of the embodiment ofthe assembly shown in FIG. 5;

FIG. 7 is a partial sectional view taken at line 7-7 of FIG. 6;

FIG. 8 is an isometric view of a portion of an example embodiment of anassembly according to the invention;

FIG. 9 is an isometric view of a portion of an example embodiment of anassembly according to the invention;

FIG. 10 is a partial sectional view of the embodiment shown in FIG. 9;

FIG. 11 is an isometric view of a portion of an embodiment of anassembly according to the invention; and

FIG. 12 is a partial sectional view of the embodiment shown in FIG. 11.

DETAILED DESCRIPTION

FIG. 1 shows an assembly 10 for connecting a branch line 12 of a firesuppression system to a sprinkler 14. Note that sprinkler is definedherein as any device which discharges a fire suppression fluid, andincludes, but is not limited to, items such as sprinklers, heads,nozzles, emitters and the like, whether they be open or closed and openin response to a fire. Assembly 10 comprises a flexible conduit 16 whichhas a first end 18 connected to the branch line 12, and a second end 20which is connected to the sprinkler 14. The branch line 12 is supportedby a pipe hanger 22 attached to a portion of the structure in which thefire suppression system is mounted, in this example, to the structuralceiling 24 of a building. Branch line 12 is one of many branch linesconnected to a riser pipe 26 in fluid communication with a pressurizedsource of a fire suppressing fluid, such as water (not shown). A portionof the assembly 10 near the second end 20 of the flexible conduit 16 isengaged by a bracket 28 that is mounted on a cross beam 30 which extendsbetween and is mounted on support rails 32 which support a decorativeceiling, such as a suspended ceiling or a drop ceiling (not shown)intended to hide the structural ceiling 24. Bracket 28 has variousembodiments; the embodiment shown in FIG. 1 is disclosed in U.S. Pat.No. 7,784,746, hereby incorporated by reference herein. Bracket 28includes sidewalls 34 and 36 connected to a back wall 38 in spacedrelation to one another so as to receive cross beam 30. Bracket 28 alsohas a u-shaped opening 40 which receives the portion of the assembly 10.A locking unit, in this example, a wire bail 42 is pivotably attached tothe sidewalls 34 and 36 and cooperates with them to affix the assemblyto the cross beam 30. FIG. 1A illustrates another example bracket 44which is disclosed in U.S. Pat. No. 7,735,787 and hereby incorporated byreference herein. Bracket 44 comprises sidewalls 46 and 48 each attachedto a back wall 50 in spaced relation to one another so as to receivecross beam 30. Bracket 44 also has a u-shaped opening 52 which receivesthe portion of the assembly 10. A locking unit, in this example, afinger 54 is pivotably attached at one end to the sidewalls 46 and 48.The opposite end is secured to the sidewalls 46 and 48 by a pivotingwing nut assembly 55 to affix the assembly to the cross beam 30.

FIG. 2 illustrates in detail an example embodiment of the assembly 10,wherein the flexible conduit 16 comprises a corrugated stainless steelhose 56 which provides a flexible yet robust fluid tight member whichresists corrosion. At the first end 18 of the assembly 10, the conduit16 (hose 56) is connected to a saddle fitting 58. The saddle fittingcomprises a saddle 60 which sealingly engages one side of the branchline 12 through an opening therein and is attached to the branch line bya strap 62 which wraps around the opposite side of the branch line 12and is bolted to the saddle 60. Although various means, such as directwelding using an adapter, or using a threaded “tee” fitting, forconnecting conduit 16 to the branch line 12 are also feasible, use ofthe saddle fitting 58 provides an advantage over these other connectionmeans because the saddle fitting can be installed anywhere along thelength of the branch line 12 merely by drilling the appropriate sizeopening in the branch line at a desired location, engaging the saddle 60with the opening, and bolting the strap 62 to the saddle 60. The saddlefitting 58 thus eliminates welding as well as the need to determine theexact position of the connection point in a design, and allows theinstaller to position the connection where it is best suited relative tothe desired position of the sprinkler 14 and the length of the conduit16. This feature saves time in both the design phase of a project aswell as during installation, as the designer need not calculate andspecify the exact location of a large number of tee fittings in asystem, and obvious errors in design can be avoided during installationsince the installer is not constrained to make the connection where atee fitting is located but is permitted greater freedom of action.

With reference again to the exploded view of FIG. 2, the connection ofthe conduit 16 to the sprinkler 14 (as well as to the branch line 12 viasaddle fitting 58) may be effected by a rotatable adapter 64. As shownin detail in FIGS. 3 and 4, the example adapter 64 is positioned betweenthe sprinkler 14 and the conduit 16. The adapter 64 has a longitudinalbore 66 and is formed of a first adapter portion 68 which is attachableto the sprinkler 14, and a second adapter portion 70 which is attachedto the end 20 of conduit 16. In this example, attachment of thesprinkler 14 to the adapter portion 68 is effected using internal screwthreads 72 (NPT threads, for example) at one end which receivecompatible external screw threads 74 of the sprinkler 14. Otherattachment means, such as brazing, welding, soldering and threadlessconnections such as bayonet mounts, are of course also feasible.

Adapter portions 68 and 70 are rotatable relatively to one another abouta longitudinal axis 74 concentric with the bore 66. By allowing theadapter portions to rotate relatively to one another, application oftorque to the conduit 16 about axis 74 is prevented, for example, whenattaching the sprinkler 14 to the adapter, or when mounting the adapteronto a bracket or other support (see also FIG. 1), as well as torquecaused by seismic activity or vibrations.

As shown in detail in FIG. 4, relative rotation between the adapterportions 68 and 70 is permitted through the use of a split ring 76.Second adapter portion 70 comprises a tube 78 attached to the end 20 ofthe conduit 16. The bore 66 of the first adapter portion 68 is sized toreceive the tube 78. The split ring 76, commercially known as a “snapring”, is used to prevent relative axial movement between the adapterportions and thereby join the conduit 16 to the sprinkler 14 whileallowing relative rotation between those parts. Split ring 76 has aninner portion 80 sized to fit within an outwardly facing circumferentialgroove 82 positioned in the outer surface 84 of tube 78. Split ring 76further has an outer portion 86 sized to fit within an inwardly facingcircumferential groove 88 positioned on an inner surface 90 of the firstadapter portion 68. Engagement between the split ring 76 and thecircumferential grooves 82 and 88 does not inhibit relative rotationbetween the adapter portions 68 and 70, but prevents relative axialmotion. The fact that the ring 76 is split allows it to be compressed orexpanded into a smaller or larger diameter by forcing the free ends ofthe ring toward or away from one another as is well understood for splitrings. This permits the ring portions to be disengaged from thecircumferential grooves in the adapter portions and thereby allowassembly and disassembly of the adapter portions 68 and 70 as is wellunderstood for split rings. One or more ring seals 92, for exampleelastomeric O-rings, are positioned between the outer surface 84 of tube78 and the inner surface 90 of the adapter portion 68 for effecting thefluid tight connection between the adapter portions. As shown in FIG. 2,the example rotatable adapter 64 may be used between the conduit 16 andthe sprinkler 14, and/or between the conduit 16 and the saddle fitting58 (or other attachment means).

FIGS. 5-7 illustrate another example of a rotatable adapter 94 which canbe used to isolate conduit 16 from torsional forces imposed about anyaxis. As shown in FIG. 5, the adapter 94 may be positioned between asprinkler 14 and the conduit 16 and/or between the conduit and theattachment means to the branch line (in this example a saddle fitting58). As shown in detail in FIGS. 6 and 7 for the attachment of thesprinkler 14 to the conduit 16, the rotatable adapter 94 comprises afirst adapter portion 96 having a concave spherical surface 98positioned at one end and surrounding a bore 100. The sprinkler 14 maybe mounted on the opposite end of the first adapter portion 96. A secondadapter portion 102 has, at one end, a convex spherical surface 104surrounding bore 100. The opposite end of the adapter portion 102 isattached to the conduit 16. The convex spherical surface 104 is sized tofit within the concave spherical surface 98 of adapter portion 96,thereby creating a ball joint which allows relative rotation between theadapter portions about any three mutually perpendicular axes, thusisolating the conduit 16 from any torsional force imposed by relativemotion between the sprinkler and the branch line, as well as from forcesapplied to the sprinkler or adapter portion 96, for example, when thesprinkler is installed or the assembly is mounted on a support. Theadapter portions 96 and 102 are held together by a retainer 106.Retainer 106 has a concave spherical surface 108 which surrounds theconvex spherical surface 104 of the second adapter portion 102. Theretainer is attached to the first adapter portion 96. In the exampleshown in FIG. 7 the retainer comprises a nut 110 which engages the firstadapter portion 96 using screw threads 112. Other attachment means arealso feasible. To ensure fluid tightness of the adapter 94 a seal 114may be positioned between the second adapter portion 102 and theretainer 106 and another seal 116 may be positioned between the retainer106 and the first adapter portion 96. The seals may be elastomericrings, such as O-rings.

FIG. 8 shows another example assembly embodiment which comprises asleeve 115 that co-axially surrounds a portion of the flexible conduit16 proximate to an adapter 117. Adapter 117 is joined to the conduit 16in this example by a union fitting 118 positioned at one end of theadapter and receives the external threads of the sprinkler (not shown)with internal threads 120 at the other end to effect attachment. Sleeve115 may be made of a durable material, such as stainless steel, and mayhave a plurality of outwardly facing flat surfaces 122 allowing it to beeasily captured by a mounting bracket, such as bracket 28 shown inFIG. 1. In the example sleeve shown in FIG. 8 there are six flatsurfaces 122 which form a hexagonal sleeve cross section.

In the embodiment shown in FIG. 8, the sleeve 115 is formed of a splitunitary body 124 having a first longitudinally extending edge 126 infacing relation with a second longitudinally extending edge 128. Theedges 126 and 128 may be in spaced relation to one another so as todefine a gap 130. This configuration allows the sleeve 115 to act as acollet with the ability to expand contract radially. In this embodimentthe sleeve 115 is free to rotate about the conduit 16 but axial motionis prevented by a pair of fixed radially projecting shoulders 132 and134. Shoulder 132 is mounted on the conduit 16 positioned between thesleeve 115 and the adapter 117 and shoulder 134 is positioned at theopposite end of the sleeve from shoulder 132. The shoulders 132 and 134project radially outwardly from the conduit 16 and capture the sleeve115 between them by engaging the ends of the sleeve.

FIGS. 9 and 10 illustrate another assembly embodiment having a sleeve136 mounted on a flexible conduit 16 with a corrugated outer surface138. The corrugated outer surface is comprised of a plurality of crests140 and troughs 142 which extend helically around and define a centralspace 144. As shown in FIG. 10, sleeve 136 has a corrugated inwardlyfacing surface 146 comprising a plurality of crests 148 and troughs 150which extend helically and are sized and spaced so as to fit within thecrests 140 and troughs 142 of the corrugated outer surface 138 of theflexible conduit 16. Engagement between the crests and troughs of thesleeve 136 and the conduit 16 prevents axial sliding motion of thesleeve relatively to the conduit, but screw action upon rotation of thesleeve 136 relative to the conduit 16 allows the sleeve to be positionedas required along the conduit so that the sprinkler (not shown) is atthe proper location relative to the decorative ceiling when the sleeve136 is received by a support such as bracket 28 (see FIG. 1). Thethreaded engagement between the sleeve 136 and the corrugated surface138 of conduit 16 allows limited rotation of the conduit relative to thesleeve (thereby preventing torque from being applied to the conduit 16)without significant axial motion of the conduit relative to the sleeve.In the example embodiment of FIG. 9, an adapter 152 is connected to theconduit 16 by a union fitting 154, the adapter having internal threads156 to receive the external threads of a sprinkler.

In another assembly embodiment, shown in FIGS. 11 and 12, the crests andtroughs 140 and 142 forming the corrugated surface 138 of the conduit 16are not helically arranged, but extend circumferentially around anddefine the central space 144. In this embodiment a sleeve 158 also has aplurality of crests 160 and troughs 162 which extend circumferentiallyaround the sleeve inner surface 164. The crests 160 and troughs 162 ofthe sleeve 158 are sized and spaced to engage the crests 140 and troughs142 of the conduit 16 and thus prevent sliding axial motion of thesleeve 158 relatively to the conduit 16 while permitting relativerotational motion between the two parts. In this embodiment, the sleeve158 is split, as evidenced by the gap 166 (see FIG. 11). This allows thesleeve 158 to be positioned axially along the conduit by elasticallydeforming the sleeve outwardly to disengage its crests and troughs fromthe troughs and crests of the conduit 16, moving the sleeve along theconduit to the desired position, and then releasing the sleeve, allowingit to return to its undeformed shape engaging the crests and troughs byvirtue of its resilient characteristics.

The embodiments provided herein show union joints by way of example, itbeing understood that other types of connections, such as fixed NPTsprinkler outlets, swivel sprinkler outlets as well as NPT adapters arealso feasible for use with the assembly according to the invention.

The assembly for connecting a sprinkler to a branch line of a firesuppression system according to the invention will provide numerousadvantages over the prior art. The assembly is easy to install on abranch line and provides great adjustability of the final position ofthe sprinkler, thereby simplifying design and installation tasks. It ismuch more difficult to over-torque the assembly due to the rotationalfreedom afforded by the rotatable adapter or the sleeve, resulting in asignificantly decreased potential for damage upon installation or duringa seismic event. Additionally, the assembly can be pressure loss testedas a unit (with or without the sprinkler installed) thereby providingthe system designer one equivalent length number indicative of head lossinstead of resorting to calculating the equivalent length as the sum ofequivalent lengths for each component of the assembly. This shouldimprove the accuracy of hydraulic calculations. Furthermore, the entireassembly, including the sprinkler head, may be K-factor tested whichwill provide a single, simplified K-factor number of increased accuracy,the K-factor being a constant of proportionality used to determine theflow rate of a nozzle as a function of the square root of the pressureat the nozzle.

While the example assembly embodiments disclosed herein are described inthe context of a fire suppression system, it is understood that thedescriptions are examples and that the assembly embodiments disclosedherein may also be used with other systems, such as hydronic systems,where a fluid is conveyed by a flexible conduit which it is desired toisolate from unwanted and potentially damaging applied torques.

What is claimed is:
 1. An assembly for connecting a sprinkler to abranch line of a fire suppression system, said assembly comprising: aflexible conduit having a first end connectable to said branch line, anda second end connectable to said sprinkler, said flexible conduit havinga corrugated outer surface, said corrugated outer surface comprising aplurality of first crests and troughs extending circumferentially aroundand defining a central space, said flexible conduit providing fluidcommunication between said branch line and said sprinkler; an adaptermounted on said second end of said flexible conduit for effectingattachment of said sprinkler to said flexible conduit; a sleeveco-axially surrounding a portion of said flexible conduit proximate tosaid adapter, said sleeve having a corrugated inwardly facing surfacecomprising a plurality of second crests and troughs extendingcircumferentially and spaced so as to fit within said first crests andtroughs and thereby prevent axial sliding motion of said sleeverelatively to said conduit, said sleeve and said flexible conduit beingrotatable relatively to one another thereby preventing torque beingapplied to said flexible conduit through said sleeve; a bracket havingan opening receiving said sleeve and a locking unit movably mounted onsaid bracket, said locking unit engaging and retaining said sleevewithin said opening; and a cross beam received by said bracket forsecuring said bracket in relation to said branch line.
 2. The assemblyaccording to claim 1, wherein said sleeve comprises a plurality of flatoutwardly facing surfaces.
 3. The assembly according to claim 2, whereinsaid sleeve comprises six flat outwardly facing surfaces forming ahexagonal cross section.
 4. The assembly according to claim 1, whereinsaid sleeve comprises a unitary body having a first longitudinallyextending edge and a second longitudinally extending edge in facingrelation with said first longitudinally extending edge.
 5. The assemblyaccording to claim 1, wherein said first longitudinally extending edgeis positioned in spaced relation to said second longitudinally extendingedge so as to define a gap therebetween.
 6. The assembly according toclaim 1, wherein said bracket comprises a plurality of sidewallsattached to one another in spaced relation to define a U-shaped opening.7. The assembly according to claim 6, wherein said locking unitcomprises a wire bale pivotably attached to said bracket.
 8. Theassembly according to claim 6, wherein said locking unit comprises afinger pivotably attached to said bracket.
 9. An assembly for connectinga sprinkler to a branch line of a fire suppression system, said assemblycomprising: a flexible conduit having a first end connectable to saidbranch line, and a second end connectable to said sprinkler, saidflexible conduit having a corrugated outer surface, said corrugatedouter surface comprising a plurality of first crests and troughsextending helically around and defining a central space, said flexibleconduit providing fluid communication between said branch line and saidsprinkler; an adapter mounted on said second end of said flexibleconduit for effecting attachment of said sprinkler to said flexibleconduit; a sleeve co-axially surrounding a portion of said flexibleconduit proximate to said adapter, said sleeve having a corrugatedinwardly facing surface comprising a plurality of second crests andtroughs extending helically and spaced so as to fit within said firstcrests and troughs and thereby prevent axial sliding motion of saidsleeve relatively to said conduit, said sleeve and said flexible conduitbeing rotatable relatively to one another thereby preventing torquebeing applied to said flexible conduit through said sleeve; a brackethaving an opening receiving said sleeve and a locking unit movablymounted on said bracket, said locking unit engaging and retaining saidsleeve within said opening; and a cross beam received by said bracketfor securing said bracket in relation to said branch line.
 10. Theassembly according to claim 9, wherein said sleeve comprises a pluralityof flat outwardly facing surfaces.
 11. The assembly according to claim10, wherein said sleeve comprises six flat outwardly facing surfacesforming a hexagonal cross section.
 12. The assembly according to claim9, wherein said sleeve comprises a unitary body having a firstlongitudinally extending edge and a second longitudinally extending edgein facing relation with said first longitudinally extending edge. 13.The assembly according to claim 12, wherein said first longitudinallyextending edge is positioned in spaced relation to said secondlongitudinally extending edge so as to define a gap therebetween. 14.The assembly according to claim 9, wherein said bracket comprises aplurality of sidewalls attached to one another in spaced relation todefine a U-shaped opening.
 15. The assembly according to claim 14,wherein said locking unit comprises a wire bale pivotably attached tosaid bracket.
 16. The assembly according to claim 14, wherein saidlocking unit comprises a finger pivotably attached to said bracket.